To relate the physiological properties of neurons to stimulus representation is central for an understanding of how sensory processing is accomplished by the neural systems. In order to resolve odorant stimuli the brain is presented with a number of perceptual challenges that make the olfactory system an attractive one in which to study this question. Odor perception appears to be highly synthetic though at the periphery odor processing is often noisy and variable. Thought to correspond to the coherent activity of cell populations, synchronized oscillations of local field potentials are a possible mechanism for converting distributed, dense stimulus representation into a sparse one, making tractable complicated pattern-learning and pattern- recognition problems. Our proposal aims to use chronic recordings in the olfactory bulb (OB) and piriform cortex from rats engaged in an olfactory discrimination task to examine how gamma1 oscillatory synchronization might aid in the resolution of spatial patterns created by arrays of activated glomeruli, how such oscillations are modified by previously experienced stimuli leading to refinement of perceptual discrimination, and the role that inhibition plays at the level of the local OB circuit in the modulation of these oscillations. [unreadable] [unreadable] [unreadable]